JP4871659B2 - License issuing device, license verification device, license issuing method, and program - Google Patents

Description

  The present invention relates to a technique for preventing illegal use of content.

  The car navigation system (hereinafter referred to as “car navigation system”) uses the map data recorded in the car navigation system to present a recommended route to the destination and display the current position of the vehicle on the map. . As a means for recording the map data, a model using a DVD or CD is known. Recently, products using a hard disk drive (hereinafter referred to as “HDD”) are becoming mainstream as means for recording map data.

  By the way, it is desirable that the map data used in the car navigation system is regularly updated to the latest data. This is because roads and buildings are newly constructed or removed, and therefore, when using old map data, the user may not be guided with high accuracy. Therefore, in the conventional DVD type (or CD type) car navigation system, the map data is updated by simply selling the disc on which the map data is recorded to the user and replacing the old disc with the old disc. Yes. On the other hand, as an update method in the case of an HDD type car navigation system, there are the following methods.

  First, when the target model has a DVD drive, there is an update method in which a master disk in which map data is recorded is distributed, inserted into the DVD drive, and copied to the HDD. In the case of a model without a DVD drive, there is a method of connecting a device having a DVD drive to a car navigation system (assuming that the interface to be connected is in the car navigation system), and copying to the HDD through the connected device. Alternatively, a removable recording medium such as an SD card can be inserted into the car navigation system and copied from the recording medium to the HDD, or the car navigation system itself can be directly connected to the network to receive the data directly from the server that distributes the map data. A way to do this is also conceivable.

  In the updating method as described above, it is necessary to restrict unauthorized copying to the HDD. Therefore, in order to limit content duplication in a terminal device (such as a car navigation system or personal computer) having such an HDD, the following techniques have been widely used in the past.

First, as a common form, when copying content to a terminal, you are forced to enter a random alphanumeric string (generally called a serial number), and only if the entered serial number is correct There is a method to allow.
However, in this method, there is a problem that if one correct serial number can be obtained, the same number can be copied to a plurality of terminals many times.

  Therefore, in recent years, a method of encrypting and distributing contents is often used. In this method, a decryption key (generally called a license) for decrypting content is distributed to the terminal by the following procedure. First, terminal-specific information (such as a hardware ID) is transmitted from a terminal to a device that issues a license (hereinafter referred to as a “license issuing device”). Upon receiving this, the license issuing device encrypts the content decryption key using the received terminal-specific information and sends it back to the terminal. This kind of technology has been used for online distribution of music data, which has been popular recently.

  In addition to the approach represented by the above-mentioned “method of encrypting and distributing content”, there is a technique described in Patent Document 1 as a technique for limiting the number of terminal devices that can be copied to a specific one. In this technology, the same one-way hash function is implemented in both the terminal device and the license issuing device, and the license is transmitted and received in the following procedure. First, a random character string and a public key of the terminal device are sent from the terminal to the license issuing device. Upon receiving these, the license issuing device encrypts the result of inputting the received character string into the one-way hash function (hash value) with the received public key, and sends it back to the terminal device. On the terminal side, the same calculation as that of the license issuing device is performed to obtain a hash value, and the data received from the license issuing device is decrypted using the secret key. If the calculated hash value and the decryption result are the same, a copy is made. Allow. Non-patent document 1 describes the one-way hash function and public key cryptography.

  The above-described “method of encrypting and distributing content” and the technique disclosed in Patent Document 1 can prevent unlimited copying of content.

JP 2003-174446 A "Introduction to Cryptography-Alice in the Secret Country", Softbank Creative: ISBN: 4797322977, 2005

  Incidentally, as described above, there are various methods for updating the map data of the HDD type car navigation system. However, since both methods require HDD rewrite processing and update license management, the threshold is higher for users who are not familiar with IT technology compared to DVD (or CD) car navigation systems (update work). Is troublesome). Therefore, it is desired to provide a map data update service in an automobile sales dealer (hereinafter referred to as “dealer”) for all generations of drivers from young people to senior citizens. Even though IT technology is progressing, not all dealers have IP communication lines. Therefore, a means for notifying update licenses using FAX that already exists in almost all dealers is considered as a practical method.

  However, the method of transmitting and receiving licenses using FAX has the following problems. Specifically, there is a problem that an incorrect license can be notified to a dealer due to a human operation error (character misrecognition / entry error) due to a problem of FAX transmission quality or the like. For example, the above-mentioned “method of encrypting and distributing content” and Patent Document 1 assume that the license is encrypted and sent. In this case, if encryption is performed with a 128-bit common key, the information to be notified (encryption license) is 128 bits at the minimum, and 22 characters can be input even if one character is 6 bits (this corresponds to Base64 encoding). Necessary. In general, humans are more likely to make mistakes by entering a long number of characters.

  Further, if the number of characters to be input is reduced and the key length is shortened, the possibility of making an input error can be reduced, but the encryption strength is lowered. Further, the above-mentioned “method of encrypting and distributing content” and Patent Document 1 assume that a license is transmitted in a bit string that is interpreted by a computer. It needs to be converted to human readable alphanumeric characters. At this time, some of the alphanumeric characters have similar shapes such as O (alphabet of O) and 0 (zero), and human misrecognition is likely to occur only by simple conversion.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the security level in a license issuance apparatus or license verification apparatus used in an environment not connected to a network. This is to reduce the possibility that the user erroneously inputs or recognizes the license.

  In order to solve the above-described problem, the first aspect of the present invention is applied to a license issuing device that issues a license for using content.

  The license issuing device includes a parameter input unit that receives input of a parameter for issuing a license, a hash calculation unit that inputs the parameter into a one-way hash function and calculates a hash value, and a bit string of predetermined bits For each combination, a storage unit storing a conversion table in which alphanumeric characters are associated, and using the conversion table, a specific portion of the bit string representing the hash value is converted into an alphanumeric character string, and the converted English A license generation unit that outputs a numeric character string as a license.

  The storage unit stores a plurality of types of conversion tables, and the license generation unit has the largest occurrence position bias for each character type out of the plurality of types of conversion tables. A conversion table to be converted into an alphanumeric character string may be selected, and the alphanumeric character string converted with the selected conversion table may be output as the license.

  In order to solve the above problem, the second aspect of the present invention is applied to a license verification apparatus that is connected to an information processing terminal that uses content and verifies a license necessary for updating the content. The

  Then, the license verification device calculates a hash value by inputting a content recording unit storing content, a parameter input unit for obtaining a parameter from the information processing terminal, and the one-way hash function. A hash table, a conversion table recording unit for storing a conversion table in which alphanumeric characters are associated with each bit string combination of predetermined bits, and a specific part of the bit string representing the hash value using the conversion table The license generation unit that generates the first license by converting the character string into the character string, the license input unit that receives the second license input from the operator, and the generated first license and the received second license are compared. If the two match, the stored content is written into the information processing terminal.

  The storage unit stores a plurality of types of the conversion tables, and the license generation unit stores, for each character string of the alphanumeric characters converted by the stored conversion tables, for each character type. A value indicating the deviation of the occurrence position is obtained, and using the value indicating the deviation, a conversion table to be converted into the alphanumeric character string having the largest deviation of the occurrence position is selected, and the selected conversion table The converted alphanumeric character string may be used as the first license.

  In the above description, the parameters are input to the one-way hash function. However, the parameters are not limited to the hash function and may be any irreversible one-way function.

  As described above, according to the present invention, the hash value is calculated, and the license is generated by converting the specific part of the bit string representing the calculated hash value into an alphanumeric character string, so the security level of the license is lowered. The number of digits can be reduced without any problem. As a result, it is possible to reduce the possibility that the user erroneously inputs or recognizes the license.

  Also, by storing multiple types of conversion tables, for each character type, select a conversion table that converts an alphanumeric character string with the greatest deviation in the occurrence position, and convert the English characters converted using the selected conversion table. Since a numeric character string is used as a license, it is possible to generate a license that is less likely to be erroneously recognized by the user. This is because the possibility of misrecognition that English letters and numbers are mixed increases.

  Therefore, if the present invention is used, for example, transmission errors caused by humans when transmitting and receiving licenses using FAX can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  This embodiment assumes a map data update system for a car navigation system (car navigation system) in an automobile sales dealer (dealer).

  First, the outline of the map data update system of this embodiment is shown in FIG.

  FIG. 13 is a schematic configuration diagram of an embodiment to which the present invention is applied.

  As shown in the figure, the map data update system includes a license issuing device 100 installed in an automobile manufacturer, car navigation manufacturer, map production company, map data sales company, etc. (hereinafter simply referred to as “maker” for convenience), a dealer, And a license verification apparatus 200 installed in the system. The license issuing device 100 accepts input of parameters (parameters will be described later) associated with the information processing terminal 300 that is a license issuance, and generates and outputs a license using the accepted parameters. The manufacturer operator transmits the output license to the dealer using a facsimile machine. In this embodiment, a case where the license issuing device 100 issues a license consisting of 10 alphanumeric characters is taken as an example.

  A dealer employee or the like (operator) receives a license transmitted from the manufacturer via the facsimile machine. The operator makes the license verification device 200 and the information processing terminal (assuming car navigation in this embodiment) 300 communicable. For example, the license verification device 200 and the information processing terminal 300 are connected by the communication line 400. The operator inputs the license received by the facsimile apparatus to the license verification apparatus 200. Further, the license verification apparatus 200 acquires a parameter from the information processing terminal 300 and generates a license using the parameter. The license verification apparatus 200 authenticates the input license using the license input by the operator and the license generated by the license verification apparatus 200, and when authenticated, the map recorded in the license verification apparatus 200. Data is written to the information processing terminal (car navigation system) 300.

  In the above description, the license verification apparatus 200 and the information processing terminal 300 are connected to each other via the communication line 400 so that they can communicate with each other. However, the present invention is not limited to this. The license verification device 200 and the information processing terminal 300 may be configured to be able to communicate with each other wirelessly.

  Next, a specific configuration of the map data update system will be described.

  First, FIG. 1 shows a functional configuration of the license issuing device of the present embodiment.

  FIG. 1 is a functional block diagram of a license issuing device according to an embodiment of the present invention.

  As illustrated, the license issuing device 100 includes a parameter input unit 101, a seed recording unit 102, a hash calculation unit 103, a license generation unit 104, a conversion table selection unit 105, a conversion table recording unit 106, and a license display unit 108. . The license issuing device 100 is connected to an input device (not shown) such as a keyboard for receiving input from an operator and a display device (not shown) such as a liquid crystal display for displaying an operation guide screen or an output screen. It is assumed that

  The parameter input unit 101 receives an input of parameters associated with the information processing terminal 300 to which a license is issued via the input device. The parameter input unit 101 displays an operation screen (for example, the screen 120 shown in FIG. 3) on the display device when receiving input of parameters. In the present embodiment, a case where a terminal ID unique to the information processing terminal 300 that issues a license and a content ID that identifies content used by the information processing terminal 300 are used as parameters will be described as an example.

  The seed recording unit 102 stores a license seed (secret information managed so as not to be known to a third party) used when issuing a license.

  The hash calculation unit 103 performs one-way hash calculation using the parameters received by the parameter input unit 101 and the license seed recorded in the seed recording unit 102 as inputs. The license generation unit 104 generates an alphanumeric license using the calculated hash value.

  The conversion table recording unit 106 stores a conversion table 107 used when the license generation unit 104 converts a hash value into alphanumeric characters. In the present embodiment, the conversion table recording unit 106 stores a plurality of types of conversion tables 107. The conversion table selection unit 105 selects one appropriate conversion table 107 from a plurality of conversion tables stored in the conversion table recording unit 106.

  The license display unit 108 displays the license generated by the license generation unit 104. Specifically, the license display unit 108 displays a screen showing the license on the display device.

  Note that each function unit of the license issuing apparatus 100 described above may be realized by software, or realized by a circuit (ASIC (Application Specific Integrated Circuit) or the like) that is specifically designed to execute each function unit. May be.

  For example, when the license issuing device 100 is realized by software, the license issuing device 100 can be a computer (information processing device) having a CPU (Central Processing Unit), a memory, and an I / O interface. In this case, a program for realizing the functions of the parameter input unit 101, the hash calculation unit 103, the license generation unit 104, the conversion table selection unit 105, and the license display unit 108 is stored in the memory. The functions of the parameter input unit 101, the hash calculation unit 103, the license generation unit 104, the conversion table selection unit 105, and the license display unit 108 are realized by the CPU executing the program stored in the memory. Is done. The seed recording unit 102 and the conversion table recording unit 106 are formed in a predetermined area of the memory.

  Next, functional configurations of the license verification apparatus 200 and the information processing terminal 300 according to the present embodiment will be described.

  FIG. 2 is a functional block diagram of the license verification apparatus and the information processing terminal 300 according to the embodiment of this invention.

  The information processing terminal 300 includes a unique information recording unit 301 that stores information unique to the information processing terminal, and a content recording unit 302. Information specific to an information processing terminal refers to a “terminal ID” given to the information processing terminal. The content recording unit 302 stores content (here, map data) used by the information processing terminal 300 and a “content ID” for identifying the content.

  The information processing terminal 300 includes a function unit (current position detection unit, recommended route search unit, route guide unit, etc.) that realizes a car navigation function in addition to the unique information recording unit 301 and the content recording unit 302. . Note that the functional unit that realizes the above-described car navigation function is realized by an existing technology. Therefore, in the description of the present embodiment, the description of the car navigation function of the information processing terminal 300 is omitted.

  The license verification apparatus 200 includes a license input unit 201, a seed recording unit 202, a hash calculation unit 203, a license generation unit 204, a conversion table selection unit 205, a conversion table recording unit 206, a license comparison unit 208, a file operation unit 209, and a content A recording unit 210 is included.

  Here, the license verification apparatus 200 includes an input device (not shown) such as a keyboard for receiving an input from an operator, and a display device (not shown) such as a liquid crystal display for displaying an operation guide screen or an output screen. It shall be connected.

  The license input unit 201 receives a license input via an input device (not shown). Specifically, the dealer operator inputs the license received by the facsimile apparatus into the license input unit 201. The license input unit 201 receives a license input by the operator.

  The seed recording unit 202 stores the same license seed as the seed recording unit 102 of the license issuing device 100 described above.

  The hash calculation unit 203 performs a one-way hash calculation using the “terminal ID” and “content ID” acquired from the information processing terminal 300 and the “license seed” stored in the seed recording unit 202 as inputs.

  Specifically, the hash calculation unit 203 accesses the information processing terminal 300 and reads the “terminal ID” stored in the unique information recording unit 301. Further, the hash calculation unit 203 acquires the “content ID” stored in the content recording unit 302 via the file operation unit 209. Further, the hash calculation unit 203 reads “license seed” stored in the seed recording unit 202. Then, the hash calculation unit 203 performs one-way hash calculation with “terminal ID”, “content ID”, and “license seed” as inputs.

  The license generation unit 204 generates a license using the hash value calculated by the hash calculation unit 203 and the conversion table selected by the conversion table selection unit 105 in the same procedure as the license generation unit 104 of the license issuing device 100 described above. To do.

  The conversion table selection unit 205 performs the same processing as the conversion table selection unit 205 of the license issuing device 100 described above. The conversion table recording unit 206 stores the same conversion table 207 as the conversion table 107 stored in the conversion table recording unit 106 of the license issuing device 100 described above.

  The license comparison unit 208 compares the license received by the license input unit 201 with the license generated by the license generation unit 204. If both are the same as a result of comparison, the license input unit 201 recognizes the license received as valid, and notifies the file operation unit 209 to that effect. On the other hand, the license comparison unit 208 displays an error on a display device (not shown) if they are different as a result of the comparison.

  The content recording unit 210 stores the latest version of content (here, map data) used by the information processing terminal 300.

  The file operation unit 209 accesses the content recording unit 302 of the information processing terminal 300 and reads the content ID stored in the content recording unit 302 according to the request from the hash calculation unit 203. When the file operation unit 209 receives a notification of “authentication” from the license comparison unit 208, the file operation unit 209 updates the content stored in the content recording unit 302. Specifically, the file operation unit 209 reads the content (latest map data) stored in the content recording unit 210 and updates the map data in the content recording unit 302 of the information processing terminal 300.

  Note that each function unit of the license verification apparatus 200 described above may be realized by software, or realized by a circuit (ASIC (Application Specific Integrated Circuit) or the like designed exclusively for executing each function unit). May be.

  For example, when the license verification apparatus 200 is realized by software, the license verification apparatus 200 can be a computer having a CPU (Central Processing Unit), a memory, and an I / O interface. In this case, a program for realizing the functions of the license input unit 201, the hash calculation unit 203, the license generation unit 204, the conversion table selection unit 205, the license comparison unit 208, and the file operation unit 209 is stored in the memory. . The functions of the license input unit 201, the hash calculation unit 203, the license generation unit 204, the conversion table selection unit 205, the license comparison unit 208, and the file operation unit 209 execute the above-described program stored in the memory by the CPU. It is realized by doing. The seed recording unit 202, the conversion table recording unit 206, and the content recording unit 210 are formed in a predetermined area of the memory.

  Next, the flow of content update processing will be described.

  The license issuance apparatus 100 receives a license issuance request from an operator. Specifically, the parameter input unit 101 displays the license issuance screen 120 shown in FIG. 3 and accepts a license issuance request from the operator.

  FIG. 3 is a diagram illustrating an example of a license issuance screen according to the present embodiment.

  As illustrated, the license issuance screen 120 includes an input field 121 for inputting the “terminal ID” of the information processing terminal 300 to which the content is written, an input field 122 for inputting the “content ID” of the content to be written, and a license issuance process. Button 123 for accepting the start of the license and an output field 124 for outputting the created license. The operator inputs “terminal ID” and “content ID” in the input fields 121 and 122 on the license issuance screen 120 using an input device (not shown), respectively. Further, the operator operates an input device (not shown) and presses the button 123 on the license issuance screen 120 (selects the button 123 with a cursor or the like on the screen). When the button 123 on the license issuance screen 120 is pressed, the parameter input unit 101 outputs the input “terminal ID” and “content ID” to the hash calculation unit 103. Thereafter, the license issuing process shown in FIG. 4 is started.

  FIG. 4 is a flowchart of the license issuance process according to this embodiment.

  First, the hash calculation unit 103 performs parameter acquisition processing (S111). Specifically, the hash calculation unit 103 acquires parameters (“terminal ID” and “content ID”) from the parameter input unit 101.

  Next, the hash calculation unit 103 accesses the seed recording unit 102 and acquires the license seed recorded in the seed recording unit 102 (S112). The license seed may have any value, but should have a sufficiently long bit length to ensure the security level.

  Next, the hash calculation unit 103 obtains a hash value by inputting the information acquired in S111 and S112 into the one-way hash function (S113). Here, the unidirectional hash function may be any function, but in the following description, it is assumed that the output hash value is 160 bits. As the hash function for outputting 160 bits, for example, SHA-1 (Secure Hash Algorithm 1) adopted as the government standard hash function by the US National Standards Technology Office can be used. In the above description, the parameters are input to the one-way hash function. However, the parameters are not limited to the hash function and may be any irreversible one-way function.

  Next, the license generation unit 104 and the conversion table selection unit 105 perform processing for generating a license (S114). Specifically, the optimum conversion table 107 is selected from a plurality of conversion tables 107 in the conversion table recording unit 106, and the hash calculation unit 103 calculates using the selected conversion table 107. Convert the hash value to alphanumeric and generate a license. The process for generating the license will be described in detail later.

  Finally, the license display unit 108 displays the generated license in the output field 124 (see FIG. 3) on the screen 120 (S115). In the present embodiment, the generated license is displayed on the screen, but this is merely an example. For example, a printer may be connected to the license issuing device 100 and the license may be output to a paper medium using the printer.

  Next, the license generation process in S114 of FIG. 4 will be specifically described.

  First, a conversion table used for license generation processing will be described with reference to FIG.

  FIG. 5 is a diagram schematically showing the data structure of the conversion table used for the license generation process of this embodiment.

  The conversion table 107 is a table for converting a 6-bit bit string expressed in binary numbers into one alphanumeric character. FIG. 5 shows an example of a conversion table for converting a 6-bit bit string indicating the combination of the upper 3 bits 161 and the lower 3 bits of the combination 162 into one alphanumeric character. In the illustrated example, only one conversion table 107a among the plurality of conversion tables 107a to 107n is shown. In the present embodiment, the alphanumeric character means an alphabet (alphabet) and a number. Then, 26 types of capital letters “A to Z” and 26 types of small letters “az” are used as alphabets. Ten numbers of “0-9” are used as numbers.

  In the conversion table 107a shown in the figure, a 6-bit bit string “000000” is associated with the letter “A”. According to this example, the 6-bit bit string “000000” is converted to the letter “A”. A 6-bit bit string “111000” is associated with the numeral “4”. According to this example, the 6-bit bit string “111000” is converted to the number “4”. There are no assignable alphanumeric characters in the bits “111110” and “111111”, but these values may be handled as “000000” and “000001”, respectively.

  Next, the license generation process in S114 of FIG. 4 will be specifically described.

  FIG. 6 is a flowchart showing details of the license generation process of S114 shown in FIG. It is assumed that M conversion tables 107 are stored in the conversion table recording unit 106 (M is an integer). The conversion table 107 is assigned “number i (0 ≦ i ≦ M−1: i is an integer variable)” from “0” to “M−1”. That is, the conversion table 107 can be specified by the number i assigned to the conversion table 107.

  In the following description, “h” indicates a 160-bit hash value calculated in S113 of FIG. “K”, “w”, and “min” indicate integer variables. “Str” and “key” indicate an array of character strings. “TABLE” indicates an array for storing the conversion table 107. “F ()” is a function for generating a character string from the hash value and the conversion table 107, and “g ()” is a function for calculating the weight of the specified character string (the weight will be described later). ing.

  Hereinafter, the process of each step shown in the figure will be described.

  First, in S131, the conversion table selection unit 105 initializes variables. Specifically, the conversion table selection unit 105 initializes the number “i” of the conversion table 107 and the variable “k (0 ≦ k ≦ M)” indicating the optimal number of the conversion table 107 to “0”. Also, “min” indicating the minimum weight of the alphanumeric character string is set to “MAX_INT (maximum integer value)”.

Next, the conversion table selection unit 105 outputs the conversion table 107 having the number i among the plurality of conversion tables 107 stored in the conversion table recording unit 106 to the license generation unit 104. The license generation unit 104 substitutes the “160-bit hash value (h)” calculated in S113 of FIG. 4 and the conversion table 107 of the number i from the conversion table selection unit 105 into the following (Equation 1). Then, the “160-bit hash value (h)” is converted into a “10-character alphanumeric character string (str [i])” (S132). The conversion process for converting the hash value into an alphanumeric character string will be described with reference to FIG.
str [i] = f (h, TABLE [i]) (Formula 1)
Next, the conversion table selection unit 105 performs weighting calculation processing on the alphanumeric character string (str [i]) generated in S132 (S133). Specifically, the weight (w) is obtained by substituting the alphanumeric character string (str [i]) generated in S133 into the following (Formula 2). This weighting calculation process will be described later with reference to FIG.
w = g (str [i]) (Expression 2)
Next, the conversion table selection unit 105 compares the weight (w) obtained in S134 with “min” indicating the minimum weight of the alphanumeric character string (S134). If the weight (w) determined in S134 is less than “min” indicating the minimum weight of the alphanumeric character string, the process proceeds to S135. On the other hand, if the weight (w) obtained in S134 is not less than “min” indicating the minimum weight of the alphanumeric character string, that is, if the weight (w) is larger, the process proceeds to S136.

  Note that the process of S134 is performed M times. However, in the process of S134 performed first after the initialization process of S131, “w <min” is set, and the process proceeds to S135. That is, the weight (w = g (str [0])) obtained from the alphanumeric character string (str [0]) converted using the conversion table 107 with the number “i” being “0”, the minimum When “min” indicating a value is compared, “w <min”. This is because “min” is set to “MAX_INT (maximum integer value)” in the initialization process of S131.

  In S135, the conversion table selecting unit 105 sets “i” as the variable “k” for specifying the optimal conversion table 107 number used for generating the license, and sets “min” as “w” (“k”). ”=“ I ”,“ min ”=“ w ”). That is, the number “k” that identifies the conversion table 107 used for generating the license is used to convert the alphanumeric character string (str [i]) having the weight (w) determined as “w <min” in S134. The number is “i” in the conversion table 107.

  In S136, the conversion table selection unit 105 increments “i” (adds “1” to “i”), and proceeds to S137.

  In S137, the conversion table selection unit 105 determines whether “i” is less than “M”. If “i” is less than “M”, the process returns to S132. If “i” is not less than “M”, the conversion table selection unit 105 selects the conversion table 107 of “k” from among the plurality of conversion tables 107 as the optimal conversion table, and proceeds to the process of S138. To do.

  In S138, the license generation unit 104 uses the “k” number conversion table 107 selected in S137 to obtain an alphanumeric character string (str [k]) according to (Equation 1) described above. The alphanumeric character string (str [k]) is used as a license (key), and the process ends.

  Next, the process of converting from the hash value to the alphanumeric character string performed in S132 of FIG. 6 will be described with reference to FIG.

  FIG. 7 shows an explanatory diagram of the process of converting the hash value into an alphanumeric character string in S132 of FIG.

  As illustrated, the hash value 141 is information represented by a 160-bit bit string. The license generation unit 104 converts the data of the upper 60-bit bit string in the 160-bit hash value 141 into a 10-character alphanumeric character string. In the present embodiment, information from the 61st bit onward is discarded.

  Specifically, the license generation unit 104 includes ten conversion units 142. Each of the conversion units 142 converts 6-bit information into one alphanumeric character using the conversion table 107. Then, by combining the outputs of the ten conversion units 142, a 10-digit alphanumeric character string is generated. FIG. 7 is a diagram used for convenience of description, and is not particularly limited to this configuration. For example, even when the license generation unit 104 is realized by hardware logic, the configuration is not necessarily limited to the configuration having ten conversion units 142 as hardware devices.

  Further, in the illustrated example, the upper 60 bits of data are converted into 10 alphanumeric characters by the 10 conversion units 142, but the present invention is not limited to this. The number of conversion units 142 may be changed. For example, a single conversion unit 142 may convert upper 60-bit data into a 10-character alphanumeric character string. In this case, the conversion unit 142 may convert the bit string into an alphanumeric character string of one character every 6 bits in order from the top, and this may be performed 10 times.

  Next, the process of calculating the weight of the converted alphanumeric character string performed in S133 of FIG. 6 will be described with reference to FIG.

  FIG. 8 is a flowchart of the process of calculating the weight of the alphanumeric character string in S133 of FIG.

  Here, “str” indicates an alphanumeric character string (alphanumeric character string of the output 143 in FIG. 7) obtained as a result of conversion in S132 of FIG. “J” is an integer variable indicating the order counted from the top of the alphanumeric character string. “W” indicates an integer variable indicating the weight. “N” indicates the number of digits of the alphanumeric character string (10 digits in this embodiment). Hereinafter, the process of each step shown in the figure will be described.

  First, the conversion table selection unit 105 initializes variables in S151. Specifically, “j” is initialized to “0”, and “w” is initialized to “0”.

  In S152 to S156, the conversion table selection unit 105 scans the given alphanumeric character string from the top, and if it is an alphabetic character, adds the distance (number of digits) from the top (= 0) to the weight w, In some cases, the distance (number of digits) from the end (= alphanumeric character string length) is added to the weight w.

  Specifically, after S151, the conversion table selection unit 105 determines whether or not the first character (str [0]) of the alphanumeric character string (str) is an English character. The process proceeds to S153, and if not an English character, the process proceeds to S154 (S152).

In S153, the conversion table selecting unit 105 calculates the weight “w” using the following (Equation 3). For example, if “w” and “j” are “0”, “w” becomes “0”.
w = w + j (Formula 3)
In S154, the conversion table selecting unit 105 calculates the weight “w” using the following (formula 4). For example, if “w” and “j” are “0”, “N” is “10”, so “w” is “9”.
w = w + (N−j−1) (Formula 4)
In S155, the conversion table selection unit 105 increments “j”. If “j” is less than “N” in S156, the process returns to S152. That is, the conversion table selection unit 105 performs weighting by sequentially scanning alphanumeric character strings from the top (0). As a result of this process, “w” is smaller for character strings in which English characters are biased near the beginning of the character string and numbers are biased near the end of the character string.

  Then, by repeating S132 to S137 (see FIG. 6) including the above-described weighting processing, a conversion table for converting an alphanumeric character string near the beginning of the character string and a number near the end of the character string. 107 is selected. Then, by using the alphanumeric character string converted by the selected conversion table 107 as a license, a license for an alphanumeric character string in which the alphabet is biased near the beginning of the character string and the number is biased near the end of the character string is generated. be able to.

  The reason for generating a license for an alphanumeric character string in which alphanumeric characters are biased near the beginning of the character string and numbers are near the end of the character string is as follows. That is, when a human visually recognizes an alphanumeric character string printed on a paper medium (or an alphanumeric character string displayed on the screen), it mistakenly recognizes that English characters and numbers are mixed. The possibility is likely to increase. For example, the number “zero” and the letter “o” are similar and confusing. In this embodiment, a license can be generated in which English characters are biased near the beginning of the character string and numbers are biased near the end of the character string. The possibility can be reduced.

  Also, when inputting a license to a keyboard or the like, it is considered that there is a high possibility of erroneous input if English letters and numbers are mixed. In the present embodiment, it is possible to generate a license in which English characters are biased near the beginning of the character string and numbers are biased near the end of the character string, so that the possibility of erroneous input of the license can be reduced.

  Note that the process of calculating the weight of the alphanumeric character string shown in FIG. 8 is merely an example, and is not particularly limited thereto.

  For example, weighting may be performed so that the conversion table 107 for converting an alphanumeric character string near the end of the character string and a number biased near the beginning of the character string is selected. In this case, in the processing of S152 to S154, the distance (number of digits) from the end is added to the weight w when it is an alphabetic character, and the distance (number of digits) from the head (= 0) is weighted w when it is a number. Add to this.

  Further, for example, regarding the process of calculating the weight of the alphanumeric character string, the process according to the following procedure may be performed instead of the process shown in FIG. Specifically, instead of the process of FIG. 8, a process of selecting a conversion table that minimizes the sum of weights set in advance for each character may be performed. Hereinafter, another example of the weighting process will be described with reference to FIGS. 9 and 10.

  FIG. 9 shows an implementation method different from FIG. 8 for the process of calculating the weight in S133 of FIG. FIG. 10 is a diagram showing an example of a table used for the weighting process shown in FIG.

  The processing for calculating the weighting shown in FIG. 9 is obtained by replacing the processing from S152 to S154 in FIG. 8 with step S160. Below, it demonstrates centering on a different part from the process of FIG.

  In S160, the “return value” of the function h (x) that returns the weight for each character is added to the “weight w”. Specifically, the conversion table selection unit 105 holds a table 1000 shown in FIG. 10 in which a “return value” indicating a weight is associated with each alphanumeric character.

  In the table 1000, the “return value” of characters that are likely to be erroneously recognized is made larger than the “return value” of other characters. In the example shown in the figure, “O (O)” and “0 (zero)”, which are characters that are likely to be erroneously recognized, are returned as other characters (“O (O)” and “0 (zero)). It is larger than the “return value” of characters other than “”.

  In step S <b> 160, the conversion table selection unit 105 performs weighting calculation of the alphanumeric character string (str) using the table 1000. For example, when the i-th character from the top of the alphanumeric character string (str) is “O (O)”, the conversion table selection unit 105 adds “return value 5” to “weight w”. When the i-th character from the top of the alphanumeric character string (str) is “A”, “return value 0” is added to “weight w”. As a result, the “weight w” of an alphanumeric character string that includes characters that are likely to be erroneously recognized (“O (O)” and “0 (zero)” in the above)) is likely to be erroneously recognized. The value is larger than the “weight w” of an alphanumeric character string that does not include a possible character.

  Then, by repeating S132 to S137 (see FIG. 6) including the above-described weighting process, the conversion table 107 to be converted into an alphanumeric character string that does not include characters that are likely to be erroneously recognized is selected. It becomes. By using the character string converted by the selected conversion table 107 as a license, it is possible to generate a license for an alphanumeric character string that does not include characters that are likely to be erroneously recognized.

  In the above description, “O (o)” and “0 (zero)” are given as characters that are likely to be erroneously recognized, but this is merely an example. For example, the lowercase alphabetic character “l” and the number “1” are weighted in the same way as the above-described “O” and “0” as easily misrecognized characters. Processing may be performed.

  Next, a license verification process in the license verification apparatus 200 will be described.

  The license verification apparatus 200 receives a content update request from an operator. Specifically, the license input unit 201 of the license verification apparatus 200 displays a content update screen 220 shown in FIG. 11 on a display device (not shown) and accepts a request for content update processing.

  FIG. 11 is a diagram showing an example of a content update screen 220 in the license verification apparatus 200.

  The license verification device 200 displays a content update screen 220 on a display device (not shown) and accepts a request for content update processing. Specifically, the content update screen 220 includes an input field 221 for inputting a license, and a content update button 222 that is pressed when the content is updated.

  The operator receives the license transmitted from the manufacturer by the facsimile apparatus. The operator inputs “license” in the input field 221 of the content update screen 220 using an input device (not shown). Then, the operator operates an input device (not shown) and presses the content update button 222 on the content update screen 220 (selects the button 121 with a cursor or the like). When the content update button 222 is pressed, the license input unit 201 notifies the hash calculation unit 203 that a request for content update processing has been received. Thereafter, the content update process shown in FIG. 12 is disclosed.

  FIG. 12 is a flowchart of the content update process of the present embodiment.

  First, the license authentication apparatus 200 acquires “terminal ID” and “content ID” from the information processing terminal 300 via the communication line 400 (S211). Specifically, the hash calculation unit 203 acquires the “terminal ID” stored in the unique information recording unit 301 of the information processing terminal 300 via the communication line 400. In addition, the hash calculation unit 203 acquires a “content ID” stored in the content recording unit 302 of the information processing terminal 300 via the communication line 400. The “content ID” is acquired via the file operation unit 209.

  Next, the hash calculation unit 203 acquires “license seed” from the seed recording unit 202 (S212).

  Next, the hash calculation unit 203 performs one-way hash calculation using the acquired “terminal ID”, “content ID”, and “license seed” (S213). The hash calculation performed in this step is the same as the hash calculation performed in S113 of FIG. 4 described above.

  Next, a license generation process is performed by the license generation unit 204 and the conversion table selection unit 205 (S214). The license generation process performed in this step is the same as that performed in S114 of FIG. 4 described above. The license generated here is hereinafter referred to as a “first license”. Then, the license generation unit 204 outputs the generated “first license” to the license comparison unit 208.

  Next, a license acquisition process is performed by the license comparison unit 208 (S215). Specifically, upon receiving the “first license” from the license generation unit 208, the license comparison unit 208 acquires the license input in the license input field 221 of the content update screen 220 from the license input unit 201. . Hereinafter, for convenience of explanation, the license acquired from the license input unit 101 is referred to as a “second license”.

  Next, the license comparison unit 208 compares the “first license” and the “second license” (S 216), and if both values are the same, notifies the file operation unit 209 to that effect. Then, the process proceeds to S217. On the other hand, if both values are not the same, the license comparison unit 208 proceeds to the process of S218.

  In S217, the file operation unit 209 writes the data recorded in the content recording unit 210 into the content recording unit 302 of the information processing terminal 300, and ends the process.

  On the other hand, the process of S218, which is performed when it is determined in S216 that the “first license” and the “second license” are not the same, will be described. In S218, the license comparison unit 208 displays an error on a display device (not shown) and ends the process (S218).

  As described above, according to the present embodiment, it is possible to reduce the number of digits without lowering the security level and reduce the occurrence rate of characters that are likely to cause human misrecognition when sending and receiving licenses by FAX. Become.

  The present invention is not limited to the embodiment described above, and various modifications can be made within the scope of the gist of the present invention.

  For example, in the above description of the embodiment, the case where the content used in the car navigation system is updated has been described, but the present invention is not particularly limited thereto. The license issuing device and the license authentication device of the present embodiment can be used when it is necessary to issue a license for using content to a device that is not connected to a network. It can be applied to devices where network connection is not widespread, such as devices and display devices installed outdoors.

  In the above embodiment, each alphanumeric character string converted in each conversion table is weighted, and the conversion table used for converting the alphanumeric character string with the minimum weight is selected. Only. For example, in the alphanumeric character string weighting calculation, a large weight may be given to an alphanumeric character string in which English characters are biased near the beginning of the character string and numbers are biased near the end of the character string. Alternatively, in the example of FIG. 9, the weight given to a character that is likely to be erroneously recognized may be made smaller than the weight given to other characters. When such weighting is performed, a conversion table used for conversion of an alphanumeric character string having the maximum weight may be selected.

  In the above embodiment, the content to be updated is map data as an example, but this is only an example. Any data used in the information processing terminal may be a program, game software, music data or video data.

  In the description of the above-described embodiment, the license is notified to the operator who updates the content by facsimile, but the license may be notified by other methods. For example, the manufacturer may mail the paper medium on which the license is printed to the dealer.

It is a functional block diagram of the license issuing apparatus of embodiment of this invention. It is a functional block diagram of the license verification apparatus and information processing terminal 300 of the embodiment of the present invention. It is the figure which showed an example of the license issue screen of this embodiment. It is a flowchart of the license issue process of this embodiment. It is the figure which showed the data structure of the conversion table utilized for the license production | generation process of this embodiment in simulation. 6 is a flowchart showing details of a license generation process in S114 shown in FIG. FIG. 7 is an explanatory diagram of a process of converting a hash value into an alphanumeric character string in S132 of FIG. It is a flowchart of the process which calculates the weight of the alphanumeric character string of S133 of FIG. The processing for calculating the weight in S133 in FIG. 6 shows a different implementation method from that in FIG. It is the figure which showed an example of the table utilized for the weighting process shown in FIG. It is the figure which showed an example of the content update screen 220 in the license verification apparatus 200. FIG. It is a flowchart of the content update process of this embodiment. 1 is a schematic configuration diagram of an embodiment to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... License issuing apparatus, 101 ... Parameter input part, 102 ... Seed recording part, 103 ... Hash calculation part, 104 ... License generation part, 105 ... Conversion table selection part, 106 ... Conversion table recording part, 107 ... Conversion table, DESCRIPTION OF SYMBOLS 108 ... License display part 142 ... Conversion part 200 ... License verification apparatus 201 ... License input part 202 ... Seed recording part 203 ... Hash calculation part 204 ... License generation part 205 ... Conversion table selection part 206 ... Conversion table recording unit, 207 ... Conversion table, 208 ... License comparison unit, 209 ... File operation unit, 210 ... Content recording unit, 300 ... Information processing terminal, 301 ... Unique information recording unit, 302 ... Content recording unit, 400 ... Communication line

Claims (14)

A license issuing device that issues a license to use content,
A parameter input unit that accepts input of parameters for issuing a license;
A hash calculator that calculates the hash value by inputting the parameter into a one-way hash function;
A storage unit that stores a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits;
Using the conversion table, a specific part of the bit string representing the hash value is converted into an alphanumeric character string, and a license generating unit that outputs the converted alphanumeric character string as a license , and
The storage unit stores a plurality of types of the conversion tables,
The license generation unit
From the plurality of types of conversion tables, select a conversion table to be converted into the alphanumeric character string having the largest occurrence position bias for each character type, and convert the alphanumeric characters converted by the selected conversion table A license issuing device that outputs a column as the license. A license issuing device that issues a license to use content,
A parameter input unit that accepts input of parameters for issuing a license;
A hash calculator that calculates the hash value by inputting the parameter into a one-way hash function;
A storage unit that stores a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits;
Using the conversion table, a specific part of the bit string representing the hash value is converted into an alphanumeric character string, and a license generating unit that outputs the converted alphanumeric character string as a license , and
The storage unit stores a plurality of types of the conversion tables,
The license generation unit
For each alphanumeric character string converted using each of the stored conversion tables, a value indicating the deviation of the occurrence position is obtained for each character type, and the value of the occurrence position is determined using the value indicating the deviation. A license issuing device, wherein a conversion table to be converted into an alphanumeric character string having the greatest bias is selected, and the alphanumeric character string converted by the selected conversion table is output as the license. A license issuing device that issues a license to use content,
A parameter input unit that accepts input of parameters for issuing a license;
A hash calculator that calculates the hash value by inputting the parameter into a one-way hash function;
A storage unit that stores a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits;
Using the conversion table, a specific part of the bit string representing the hash value is converted into an alphanumeric character string, and a license generating unit that outputs the converted alphanumeric character string as a license , and
The storage unit stores a plurality of types of the conversion tables,
The license generation unit
For each character, it holds character characteristic information associated with a predetermined weight,
For each alphanumeric character string converted using each of the stored conversion tables, the character characteristic information is used to obtain a sum of weights for each character of the alphanumeric character string, and the sum of the weights A license issuing device that selects a conversion table to be converted into an alphanumeric character string that minimizes the number, and outputs the alphanumeric character string converted by the selected conversion table as the license. The license issuing device according to claim 3 ,
The character characteristic information is characterized in that a character having a large value is associated with a character that is presumed to be erroneously recognized as compared with a weight associated with a character other than the estimated character. License issuing device. The license issuing device according to any one of claims 1 to 4 ,
Data used for calculation of the hash value, and having a seed recording unit that stores a license seed managed so as not to be known to a third party,
The hash calculation unit, when calculating the hash value, further inputs the license seed to the one-way hash function in addition to the parameter. A license verification apparatus that is connected to an information processing terminal that uses content and verifies a license necessary for updating the content,
A content recording unit storing content;
A parameter input unit for acquiring parameters from the information processing terminal;
A hash calculator that calculates the hash value by inputting the parameter into a one-way hash function;
A conversion table recording unit for storing a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits;
A license generation unit that generates a first license by converting a specific part of a bit string representing the hash value into an alphanumeric character string using the conversion table;
A license input unit for receiving an input of the second license from the operator;
Comparing the second license receiving the first license to the product, if they match, and a write non-writing unit writes the information processing terminal the content that the stored,
The storage unit stores a plurality of types of the conversion tables,
The license generation unit
For each alphanumeric character string converted in each of the stored conversion tables, a value indicating the deviation of the occurrence position is obtained for each character type, and the deviation of the occurrence position is determined using the value indicating the deviation. A license verification apparatus, wherein a conversion table to be converted into the alphanumeric character string that becomes the largest is selected, and an alphanumeric character string converted by the selected conversion table is used as the first license. A license verification apparatus that is connected to an information processing terminal that uses content and verifies a license necessary for updating the content,
A content recording unit storing content;
A parameter input unit for acquiring parameters from the information processing terminal;
A hash calculator that calculates the hash value by inputting the parameter into a one-way hash function;
A conversion table recording unit for storing a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits;
A license generation unit that generates a first license by converting a specific part of a bit string representing the hash value into an alphanumeric character string using the conversion table;
A license input unit for receiving an input of the second license from the operator;
Comparing the second license receiving the first license to the product, if they match, and a write non-writing unit writes the information processing terminal the content that the stored,
The storage unit stores a plurality of types of the conversion tables,
The license generation unit
For each character, it holds character characteristic information associated with a predetermined weight,
For each alphanumeric character string converted in each stored conversion table, the character characteristic information is used to determine the sum of weights for each character of the alphanumeric character string, and the sum of the weights is minimized. A license verification apparatus that selects a conversion table for converting the alphanumeric character string and uses the alphanumeric character string converted by the selected conversion table as the first license. The license verification device according to claim 6 or 7 ,
Data used for calculation of the hash value, and having a seed recording unit that stores a license seed managed so as not to be known to a third party,
The hash calculation unit, when calculating the hash value, further inputs the license seed to a one-way hash function in addition to the parameter. A license issuing method performed by a license issuing device that issues a license for using content,
The license issuing device
A control device;
A storage device that stores a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits, and
The controller is
A parameter input step for accepting input of parameters for issuing a license;
A hash calculation step of calculating the hash value by inputting the parameter to a one-way hash function;
A license generating step of reading the conversion table from the storage device, converting a specific part of the bit string representing the hash value into an alphanumeric character string, and outputting the converted alphanumeric character string as a license; And
The storage device stores a plurality of types of the conversion tables,
In the license generation step,
From the plurality of types of conversion tables stored in the storage device, a conversion table to be converted into the alphanumeric character string having the largest deviation in occurrence position for each character type is selected, and the selected conversion A license issuing method , wherein an alphanumeric character string converted in a table is output as the license .   A license issuing method performed by a license issuing device that issues a license for using content,
  The license issuing device
  A control device;
  A storage device that stores a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits, and
  The controller is
  A parameter input step for accepting input of parameters for issuing a license;
  A hash calculation step of calculating the hash value by inputting the parameter to a one-way hash function;
  A license generating step of reading the conversion table from the storage device, converting a specific part of the bit string representing the hash value into an alphanumeric character string, and outputting the converted alphanumeric character string as a license; And
  The storage device stores a plurality of types of the conversion tables,
  In the license generation step,
  For each alphanumeric character string that is read and converted from each conversion table stored in the storage device, a value indicating the deviation of the occurrence position is obtained for each character type, and using the value indicating the deviation, Select a conversion table to be converted into an alphanumeric character string with the largest occurrence position bias, and output the alphanumeric character string converted in the selected conversion table as the license
A license issuing method characterized by:   A license issuing method performed by a license issuing device that issues a license for using content,
  The license issuing device
  A control device;
  A storage device that stores a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits, and
  The controller is
  A parameter input step for accepting input of parameters for issuing a license;
  A hash calculation step of calculating the hash value by inputting the parameter to a one-way hash function;
  A license generating step of reading the conversion table from the storage device, converting a specific part of the bit string representing the hash value into an alphanumeric character string, and outputting the converted alphanumeric character string as a license; And
  In the storage device,
  A plurality of the conversion tables;
  Character characteristic information associated with a predetermined weight is stored for each character,
  In the license generation step,
  For each alphanumeric character string converted by reading each conversion table stored in the storage device, using the character characteristic information, a sum of weights for each character of the alphanumeric character string is obtained, Select a conversion table to be converted into an alphanumeric character string having the smallest sum of weights, and output the alphanumeric character string converted in the selected conversion table as the license.
A license issuing method characterized by: The computer, a program for causing a process of issuing a license to use the content as an information processing apparatus,
The information processing apparatus includes:
A storage device is provided for storing a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits,
The program is
A parameter input step for accepting input of parameters for issuing a license;
A hash calculation step of calculating the hash value by inputting the parameter to a one-way hash function;
Reading the conversion table from the storage device, converting a specific part of the bit string representing the hash value into an alphanumeric character string, and outputting the converted alphanumeric character string as a license; Let the computer run ,
The storage device stores a plurality of types of the conversion tables,
In the license generation step,
From the plurality of types of conversion tables stored in the storage device, a conversion table to be converted into the alphanumeric character string having the largest deviation in occurrence position for each character type is selected, and the selected conversion A program characterized in that an alphanumeric character string converted in a table is output as the license .   A program for causing a computer to function as an information processing device for issuing a license for using content,
  The information processing apparatus includes:
  A storage device is provided for storing a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits,
  The program is
  A parameter input step for accepting input of parameters for issuing a license;
  A hash calculation step of calculating the hash value by inputting the parameter to a one-way hash function;
  Reading the conversion table from the storage device, converting a specific part of the bit string representing the hash value into an alphanumeric character string, and outputting the converted alphanumeric character string as a license; Let the computer run,
  The storage device stores a plurality of types of the conversion tables,
  In the license generation step,
  For each alphanumeric character string that is read and converted from each conversion table stored in the storage device, a value indicating the deviation of the occurrence position is obtained for each character type, and using the value indicating the deviation, Select a conversion table to be converted into an alphanumeric character string with the largest occurrence position bias, and output the alphanumeric character string converted in the selected conversion table as the license
A program characterized by   A program for causing a computer to function as an information processing device for issuing a license for using content,
  The information processing apparatus includes:
  A storage device is provided for storing a conversion table in which alphanumeric characters are associated with each combination of bit strings of predetermined bits,
  The program is
  A parameter input step for accepting input of parameters for issuing a license;
  A hash calculation step of calculating the hash value by inputting the parameter to a one-way hash function;
  Reading the conversion table from the storage device, converting a specific part of the bit string representing the hash value into an alphanumeric character string, and outputting the converted alphanumeric character string as a license; Let the computer run,
  In the storage device,
  A plurality of the conversion tables;
  Character characteristic information associated with a predetermined weight is stored for each character,
  In the license generation step,
  For each alphanumeric character string converted by reading each conversion table stored in the storage device, using the character characteristic information, a sum of weights for each character of the alphanumeric character string is obtained, Select a conversion table to be converted into an alphanumeric character string having the smallest sum of weights, and output the alphanumeric character string converted in the selected conversion table as the license.
A program characterized by

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